@MamaBettany
Forum rules don't allow us to diagnose (and I honestly don't know what is going on here). While it's quite possible that these ketones are just because he isn't eating, given his young age complicated by the fact that he isn't eating and is T1, I'd contact my medical team if I were you. I'd ring 111 if you can't get through to someone in his team.
How are you managing on the insulin front if he isn't eating? (I see from your previous posts that he was diagnosed T1 in January?)